#ifndef CURLINC_MULTI_H
#define CURLINC_MULTI_H
/***************************************************************************
 *                                  _   _ ____  _
 *  Project                     ___| | | |  _ \| |
 *                             / __| | | | |_) | |
 *                            | (__| |_| |  _ <| |___
 *                             \___|\___/|_| \_\_____|
 *
 * Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
 *
 * This software is licensed as described in the file COPYING, which
 * you should have received as part of this distribution. The terms
 * are also available at https://curl.se/docs/copyright.html.
 *
 * You may opt to use, copy, modify, merge, publish, distribute and/or sell
 * copies of the Software, and permit persons to whom the Software is
 * furnished to do so, under the terms of the COPYING file.
 *
 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
 * KIND, either express or implied.
 *
 * SPDX-License-Identifier: curl
 *
 ***************************************************************************/
/*
  This is an "external" header file. Do not give away any internals here!

  GOALS

  o Enable a "pull" interface. The application that uses libcurl decides where
    and when to ask libcurl to get/send data.

  o Enable multiple simultaneous transfers in the same thread without making it
    complicated for the application.

  o Enable the application to select() on its own file descriptors and curl's
    file descriptors simultaneous easily.

*/

/*
 * This header file should not really need to include "curl.h" since curl.h
 * itself includes this file and we expect user applications to do #include
 * <curl/curl.h> without the need for especially including multi.h.
 *
 * For some reason we added this include here at one point, and rather than to
 * break existing (wrongly written) libcurl applications, we leave it as-is
 * but with this warning attached.
 */
#include "curl.h"

#ifdef __cplusplus
extern "C"
{
#endif

#if defined(BUILDING_LIBCURL) || defined(CURL_STRICTER)
    typedef struct Curl_multi CURLM;
#else
typedef void CURLM;
#endif

    typedef enum
    {
        CURLM_CALL_MULTI_PERFORM = -1, /* please call curl_multi_perform() or
                                          curl_multi_socket*() soon */
        CURLM_OK,
        CURLM_BAD_HANDLE,            /* the passed-in handle is not a valid CURLM handle */
        CURLM_BAD_EASY_HANDLE,       /* an easy handle was not good/valid */
        CURLM_OUT_OF_MEMORY,         /* if you ever get this, you are in deep sh*t */
        CURLM_INTERNAL_ERROR,        /* this is a libcurl bug */
        CURLM_BAD_SOCKET,            /* the passed in socket argument did not match */
        CURLM_UNKNOWN_OPTION,        /* curl_multi_setopt() with unsupported option */
        CURLM_ADDED_ALREADY,         /* an easy handle already added to a multi handle was
                                        attempted to get added - again */
        CURLM_RECURSIVE_API_CALL,    /* an api function was called from inside a
                                        callback */
        CURLM_WAKEUP_FAILURE,        /* wakeup is unavailable or failed */
        CURLM_BAD_FUNCTION_ARGUMENT, /* function called with a bad parameter */
        CURLM_ABORTED_BY_CALLBACK,
        CURLM_UNRECOVERABLE_POLL,
        CURLM_LAST
    } CURLMcode;

/* just to make code nicer when using curl_multi_socket() you can now check
   for CURLM_CALL_MULTI_SOCKET too in the same style it works for
   curl_multi_perform() and CURLM_CALL_MULTI_PERFORM */
#define CURLM_CALL_MULTI_SOCKET CURLM_CALL_MULTI_PERFORM

/* bitmask bits for CURLMOPT_PIPELINING */
#define CURLPIPE_NOTHING 0L
#define CURLPIPE_HTTP1 1L
#define CURLPIPE_MULTIPLEX 2L

    typedef enum
    {
        CURLMSG_NONE, /* first, not used */
        CURLMSG_DONE, /* This easy handle has completed. 'result' contains
                         the CURLcode of the transfer */
        CURLMSG_LAST  /* last, not used */
    } CURLMSG;

    struct CURLMsg
    {
        CURLMSG msg;       /* what this message means */
        CURL *easy_handle; /* the handle it concerns */
        union
        {
            void *whatever;  /* message-specific data */
            CURLcode result; /* return code for transfer */
        } data;
    };
    typedef struct CURLMsg CURLMsg;

/* Based on poll(2) structure and values.
 * We do not use pollfd and POLL* constants explicitly
 * to cover platforms without poll(). */
#define CURL_WAIT_POLLIN 0x0001
#define CURL_WAIT_POLLPRI 0x0002
#define CURL_WAIT_POLLOUT 0x0004

    struct curl_waitfd
    {
        curl_socket_t fd;
        short events;
        short revents;
    };

    /*
     * Name:    curl_multi_init()
     *
     * Desc:    initialize multi-style curl usage
     *
     * Returns: a new CURLM handle to use in all 'curl_multi' functions.
     */
    CURL_EXTERN CURLM *curl_multi_init(void);

    /*
     * Name:    curl_multi_add_handle()
     *
     * Desc:    add a standard curl handle to the multi stack
     *
     * Returns: CURLMcode type, general multi error code.
     */
    CURL_EXTERN CURLMcode curl_multi_add_handle(CURLM *multi_handle, CURL *curl_handle);

    /*
     * Name:    curl_multi_remove_handle()
     *
     * Desc:    removes a curl handle from the multi stack again
     *
     * Returns: CURLMcode type, general multi error code.
     */
    CURL_EXTERN CURLMcode curl_multi_remove_handle(CURLM *multi_handle, CURL *curl_handle);

    /*
     * Name:    curl_multi_fdset()
     *
     * Desc:    Ask curl for its fd_set sets. The app can use these to select() or
     *          poll() on. We want curl_multi_perform() called as soon as one of
     *          them are ready.
     *
     * Returns: CURLMcode type, general multi error code.
     */
    CURL_EXTERN CURLMcode curl_multi_fdset(CURLM *multi_handle, fd_set *read_fd_set,
                                           fd_set *write_fd_set, fd_set *exc_fd_set, int *max_fd);

    /*
     * Name:     curl_multi_wait()
     *
     * Desc:     Poll on all fds within a CURLM set as well as any
     *           additional fds passed to the function.
     *
     * Returns:  CURLMcode type, general multi error code.
     */
    CURL_EXTERN CURLMcode curl_multi_wait(CURLM *multi_handle, struct curl_waitfd extra_fds[],
                                          unsigned int extra_nfds, int timeout_ms, int *ret);

    /*
     * Name:     curl_multi_poll()
     *
     * Desc:     Poll on all fds within a CURLM set as well as any
     *           additional fds passed to the function.
     *
     * Returns:  CURLMcode type, general multi error code.
     */
    CURL_EXTERN CURLMcode curl_multi_poll(CURLM *multi_handle, struct curl_waitfd extra_fds[],
                                          unsigned int extra_nfds, int timeout_ms, int *ret);

    /*
     * Name:     curl_multi_wakeup()
     *
     * Desc:     wakes up a sleeping curl_multi_poll call.
     *
     * Returns:  CURLMcode type, general multi error code.
     */
    CURL_EXTERN CURLMcode curl_multi_wakeup(CURLM *multi_handle);

    /*
     * Name:    curl_multi_perform()
     *
     * Desc:    When the app thinks there is data available for curl it calls this
     *          function to read/write whatever there is right now. This returns
     *          as soon as the reads and writes are done. This function does not
     *          require that there actually is data available for reading or that
     *          data can be written, it can be called just in case. It returns
     *          the number of handles that still transfer data in the second
     *          argument's integer-pointer.
     *
     * Returns: CURLMcode type, general multi error code. *NOTE* that this only
     *          returns errors etc regarding the whole multi stack. There might
     *          still have occurred problems on individual transfers even when
     *          this returns OK.
     */
    CURL_EXTERN CURLMcode curl_multi_perform(CURLM *multi_handle, int *running_handles);

    /*
     * Name:    curl_multi_cleanup()
     *
     * Desc:    Cleans up and removes a whole multi stack. It does not free or
     *          touch any individual easy handles in any way. We need to define
     *          in what state those handles will be if this function is called
     *          in the middle of a transfer.
     *
     * Returns: CURLMcode type, general multi error code.
     */
    CURL_EXTERN CURLMcode curl_multi_cleanup(CURLM *multi_handle);

    /*
     * Name:    curl_multi_info_read()
     *
     * Desc:    Ask the multi handle if there is any messages/informationals from
     *          the individual transfers. Messages include informationals such as
     *          error code from the transfer or just the fact that a transfer is
     *          completed. More details on these should be written down as well.
     *
     *          Repeated calls to this function will return a new struct each
     *          time, until a special "end of msgs" struct is returned as a signal
     *          that there is no more to get at this point.
     *
     *          The data the returned pointer points to will not survive calling
     *          curl_multi_cleanup().
     *
     *          The 'CURLMsg' struct is meant to be very simple and only contain
     *          very basic information. If more involved information is wanted,
     *          we will provide the particular "transfer handle" in that struct
     *          and that should/could/would be used in subsequent
     *          curl_easy_getinfo() calls (or similar). The point being that we
     *          must never expose complex structs to applications, as then we will
     *          undoubtably get backwards compatibility problems in the future.
     *
     * Returns: A pointer to a filled-in struct, or NULL if it failed or ran out
     *          of structs. It also writes the number of messages left in the
     *          queue (after this read) in the integer the second argument points
     *          to.
     */
    CURL_EXTERN CURLMsg *curl_multi_info_read(CURLM *multi_handle, int *msgs_in_queue);

    /*
     * Name:    curl_multi_strerror()
     *
     * Desc:    The curl_multi_strerror function may be used to turn a CURLMcode
     *          value into the equivalent human readable error string. This is
     *          useful for printing meaningful error messages.
     *
     * Returns: A pointer to a null-terminated error message.
     */
    CURL_EXTERN const char *curl_multi_strerror(CURLMcode);

/*
 * Name:    curl_multi_socket() and
 *          curl_multi_socket_all()
 *
 * Desc:    An alternative version of curl_multi_perform() that allows the
 *          application to pass in one of the file descriptors that have been
 *          detected to have "action" on them and let libcurl perform.
 *          See manpage for details.
 */
#define CURL_POLL_NONE 0
#define CURL_POLL_IN 1
#define CURL_POLL_OUT 2
#define CURL_POLL_INOUT 3
#define CURL_POLL_REMOVE 4

#define CURL_SOCKET_TIMEOUT CURL_SOCKET_BAD

#define CURL_CSELECT_IN 0x01
#define CURL_CSELECT_OUT 0x02
#define CURL_CSELECT_ERR 0x04

    typedef int (*curl_socket_callback)(CURL *easy,      /* easy handle */
                                        curl_socket_t s, /* socket */
                                        int what,        /* see above */
                                        void *userp,     /* private callback
                                                            pointer */
                                        void *socketp);  /* private socket
                                                            pointer */
    /*
     * Name:    curl_multi_timer_callback
     *
     * Desc:    Called by libcurl whenever the library detects a change in the
     *          maximum number of milliseconds the app is allowed to wait before
     *          curl_multi_socket() or curl_multi_perform() must be called
     *          (to allow libcurl's timed events to take place).
     *
     * Returns: The callback should return zero.
     */
    typedef int (*curl_multi_timer_callback)(CURLM *multi,    /* multi handle */
                                             long timeout_ms, /* see above */
                                             void *userp);    /* private callback
                                                                 pointer */

    CURL_EXTERN CURLMcode CURL_DEPRECATED(7.19.5, "Use curl_multi_socket_action()")
        curl_multi_socket(CURLM *multi_handle, curl_socket_t s, int *running_handles);

    CURL_EXTERN CURLMcode curl_multi_socket_action(CURLM *multi_handle, curl_socket_t s,
                                                   int ev_bitmask, int *running_handles);

    CURL_EXTERN CURLMcode CURL_DEPRECATED(7.19.5, "Use curl_multi_socket_action()")
        curl_multi_socket_all(CURLM *multi_handle, int *running_handles);

#ifndef CURL_ALLOW_OLD_MULTI_SOCKET
/* This macro below was added in 7.16.3 to push users who recompile to use
   the new curl_multi_socket_action() instead of the old curl_multi_socket()
*/
#define curl_multi_socket(x, y, z) curl_multi_socket_action(x, y, 0, z)
#endif

    /*
     * Name:    curl_multi_timeout()
     *
     * Desc:    Returns the maximum number of milliseconds the app is allowed to
     *          wait before curl_multi_socket() or curl_multi_perform() must be
     *          called (to allow libcurl's timed events to take place).
     *
     * Returns: CURLM error code.
     */
    CURL_EXTERN CURLMcode curl_multi_timeout(CURLM *multi_handle, long *milliseconds);

    typedef enum
    {
        /* This is the socket callback function pointer */
        CURLOPT(CURLMOPT_SOCKETFUNCTION, CURLOPTTYPE_FUNCTIONPOINT, 1),

        /* This is the argument passed to the socket callback */
        CURLOPT(CURLMOPT_SOCKETDATA, CURLOPTTYPE_OBJECTPOINT, 2),

        /* set to 1 to enable pipelining for this multi handle */
        CURLOPT(CURLMOPT_PIPELINING, CURLOPTTYPE_LONG, 3),

        /* This is the timer callback function pointer */
        CURLOPT(CURLMOPT_TIMERFUNCTION, CURLOPTTYPE_FUNCTIONPOINT, 4),

        /* This is the argument passed to the timer callback */
        CURLOPT(CURLMOPT_TIMERDATA, CURLOPTTYPE_OBJECTPOINT, 5),

        /* maximum number of entries in the connection cache */
        CURLOPT(CURLMOPT_MAXCONNECTS, CURLOPTTYPE_LONG, 6),

        /* maximum number of (pipelining) connections to one host */
        CURLOPT(CURLMOPT_MAX_HOST_CONNECTIONS, CURLOPTTYPE_LONG, 7),

        /* maximum number of requests in a pipeline */
        CURLOPT(CURLMOPT_MAX_PIPELINE_LENGTH, CURLOPTTYPE_LONG, 8),

        /* a connection with a content-length longer than this
           will not be considered for pipelining */
        CURLOPT(CURLMOPT_CONTENT_LENGTH_PENALTY_SIZE, CURLOPTTYPE_OFF_T, 9),

        /* a connection with a chunk length longer than this
           will not be considered for pipelining */
        CURLOPT(CURLMOPT_CHUNK_LENGTH_PENALTY_SIZE, CURLOPTTYPE_OFF_T, 10),

        /* a list of site names(+port) that are blocked from pipelining */
        CURLOPT(CURLMOPT_PIPELINING_SITE_BL, CURLOPTTYPE_OBJECTPOINT, 11),

        /* a list of server types that are blocked from pipelining */
        CURLOPT(CURLMOPT_PIPELINING_SERVER_BL, CURLOPTTYPE_OBJECTPOINT, 12),

        /* maximum number of open connections in total */
        CURLOPT(CURLMOPT_MAX_TOTAL_CONNECTIONS, CURLOPTTYPE_LONG, 13),

        /* This is the server push callback function pointer */
        CURLOPT(CURLMOPT_PUSHFUNCTION, CURLOPTTYPE_FUNCTIONPOINT, 14),

        /* This is the argument passed to the server push callback */
        CURLOPT(CURLMOPT_PUSHDATA, CURLOPTTYPE_OBJECTPOINT, 15),

        /* maximum number of concurrent streams to support on a connection */
        CURLOPT(CURLMOPT_MAX_CONCURRENT_STREAMS, CURLOPTTYPE_LONG, 16),

        CURLMOPT_LASTENTRY /* the last unused */
    } CURLMoption;

    /*
     * Name:    curl_multi_setopt()
     *
     * Desc:    Sets options for the multi handle.
     *
     * Returns: CURLM error code.
     */
    CURL_EXTERN CURLMcode curl_multi_setopt(CURLM *multi_handle, CURLMoption option, ...);

    /*
     * Name:    curl_multi_assign()
     *
     * Desc:    This function sets an association in the multi handle between the
     *          given socket and a private pointer of the application. This is
     *          (only) useful for curl_multi_socket uses.
     *
     * Returns: CURLM error code.
     */
    CURL_EXTERN CURLMcode curl_multi_assign(CURLM *multi_handle, curl_socket_t sockfd, void *sockp);

    /*
     * Name:    curl_multi_get_handles()
     *
     * Desc:    Returns an allocated array holding all handles currently added to
     *          the multi handle. Marks the final entry with a NULL pointer. If
     *          there is no easy handle added to the multi handle, this function
     *          returns an array with the first entry as a NULL pointer.
     *
     * Returns: NULL on failure, otherwise a CURL **array pointer
     */
    CURL_EXTERN CURL **curl_multi_get_handles(CURLM *multi_handle);

/*
 * Name: curl_push_callback
 *
 * Desc: This callback gets called when a new stream is being pushed by the
 *       server. It approves or denies the new stream. It can also decide
 *       to completely fail the connection.
 *
 * Returns: CURL_PUSH_OK, CURL_PUSH_DENY or CURL_PUSH_ERROROUT
 */
#define CURL_PUSH_OK 0
#define CURL_PUSH_DENY 1
#define CURL_PUSH_ERROROUT 2 /* added in 7.72.0 */

    struct curl_pushheaders; /* forward declaration only */

    CURL_EXTERN char *curl_pushheader_bynum(struct curl_pushheaders *h, size_t num);
    CURL_EXTERN char *curl_pushheader_byname(struct curl_pushheaders *h, const char *name);

    typedef int (*curl_push_callback)(CURL *parent, CURL *easy, size_t num_headers,
                                      struct curl_pushheaders *headers, void *userp);

    /*
     * Name:    curl_multi_waitfds()
     *
     * Desc:    Ask curl for fds for polling. The app can use these to poll on.
     *          We want curl_multi_perform() called as soon as one of them are
     *          ready. Passing zero size allows to get just a number of fds.
     *
     * Returns: CURLMcode type, general multi error code.
     */
    CURL_EXTERN CURLMcode curl_multi_waitfds(CURLM *multi, struct curl_waitfd *ufds,
                                             unsigned int size, unsigned int *fd_count);

#ifdef __cplusplus
} /* end of extern "C" */
#endif

#endif
